use std::path::PathBuf;
use std::io::BufReader;
use std::io::prelude::*;
use std::fs::File;
use super::*;

/// Creates a `PackageManager` struct to hold in the needed data
/// to run our commands.
// TODO: figure out a better way to store and access the data.
//      Maybe a Vec?
// Currently actions that require multiple inputs will not work
// such as `apt-get update && apt-get upgrade`
#[derive(Debug, Clone, Default)]
pub struct PackageManager {
    pub name: String,
    pub search: (String, Option<String>),
    pub install: (String, Option<String>),
    pub uninstall: (String, Option<String>),
    pub sup: (String, Option<String>),
    pub purge: (String, Option<String>),
    pub update: (String, Option<String>),
    pub upgrade: (String, Option<String>),
    pub cache_clear: (String, Option<String>),
    pub complete_cache_clear: (String, Option<String>),
    pub exe: PathBuf,
}

/// This holds the various implementations of `PackageManagers` so far.
impl PackageManager {
    pub fn pacmatic() -> PackageManager {
        PackageManager {
            name: "pacmatic".to_string(),
            search: ("pacmatic".to_string(), Some("-Ss".to_string())),
            install: ("pacmatic".to_string(), Some("-S".to_string())),
            uninstall: ("pacmatic".to_string(), Some("-R".to_string())),
            sup: ("pacmatic".to_string(), Some("-Syu".to_string())),
            purge: ("pacmatic".to_string(), Some("-Rdns".to_string())),
            upgrade: ("pacmatic".to_string(), Some("-Su".to_string())),
            update: ("pacmatic".to_string(), Some("-Sy".to_string())),
            cache_clear: ("pacmatic".to_string(), Some("-Sc".to_string())),
            complete_cache_clear: ("pacmatic".to_string(), Some("-Scc".to_string())),
            exe: PathBuf::from("/bin/pacmatic"),
        }
    }

    pub fn pacman() -> PackageManager {
        PackageManager {
            name: "pacman".to_string(),
            search: ("pacman".to_string(), Some("-Ss".to_string())),
            install: ("pacman".to_string(), Some("-S".to_string())),
            uninstall: ("pacman".to_string(), Some("-R".to_string())),
            sup: ("pacman".to_string(), Some("-Syu".to_string())),
            purge: ("pacman".to_string(), Some("-Rdns".to_string())),
            upgrade: ("pacman".to_string(), Some("-Su".to_string())),
            update: ("pacman".to_string(), Some("-Sy".to_string())),
            cache_clear: ("pacman".to_string(), Some("-Sc".to_string())),
            complete_cache_clear: ("pacman".to_string(), Some("-Scc".to_string())),
            exe: PathBuf::from("/bin/pacman"),
        }
    }

    pub fn apt() -> PackageManager {
        PackageManager {
            name: "apt".to_string(),
            search: ("apt".to_string(), Some("search".to_string())),
            install: ("apt".to_string(), Some("install".to_string())),
            uninstall: ("apt".to_string(), Some("remove".to_string())),
            sup: ("apt".to_string(), Some("update".to_string())),
            purge: ("apt".to_string(), Some("purge".to_string())),
            upgrade: ("apt".to_string(), Some("upgrade".to_string())),
            update: ("apt".to_string(), Some("update".to_string())),
            cache_clear: ("apt".to_string(), Some("clean".to_string())),
            complete_cache_clear: ("apt-get".to_string(), Some("autoclean".to_string())),
            exe: PathBuf::from("/usr/bin/apt"),
        }
    }

    pub fn xbps() -> PackageManager {
        PackageManager {
            name: "xbps".to_string(),
            search: ("xbps-query".to_string(), Some("-Rs".to_string())),
            install: ("xbps-install".to_string(), Some("-S".to_string())),
            uninstall: ("xbps-remove".to_string(), None),
            sup: ("xbps-install".to_string(), Some("-Su".to_string())),
            purge: ("xbps-remove".to_string(), Some("-R".to_string())),
            upgrade: ("xbps-install".to_string(), Some("-Su".to_string())),
            update: ("xbps-install".to_string(), None),
            cache_clear: ("xbps-remove".to_string(), Some("-0".to_string())),
            complete_cache_clear: ("xbps-remove".to_string(), Some("-0".to_string())),
            exe: PathBuf::from("bin/xbps-install"),
        }
    }
    // allows setting the default.conf
    // TODO: put default.conf somewhere it actually belongs rather than in
    // the current folder.
    pub fn set_default(&self) -> std::io::Result<()> {
        let mut file = File::create("default.conf")?;
        file.write_all(format!("{}", self.name).as_bytes())?;
        Ok(())
    }
}

/// Reads from default.conf and returns the appropriate `PackageManager`
/// Pulls the first line out of the default.conf and loads that.
/// If it doesn't recognize the file it will tell the user that there's an
/// issue before exiting.
pub fn read_default() -> PackageManager {
    let file = File::open("default.conf").unwrap();
    let buffered = BufReader::new(file);
    for line in buffered.lines() {
        match &*line.unwrap() {
            "pacmatic" => return PackageManager::pacmatic(),
            "pacman" => return PackageManager::pacman(),
            "apt" => return PackageManager::apt(),
            "xbps" => return PackageManager::xbps(),
            _ => {
                println!("Default either not set or has been changed");
                std::process::exit(1)
            }
        }
    }
    PackageManager::default()
}